When Anita Disney was growing up in Adelaide, Australia, friends and family assumed she would become a scientist. After all, her father was a biologist and one of the founding faculty members of Flinders University.
But in what she admits may have been a bit of youthful rebellion, Disney gained admission to a performing arts magnet high school and threw herself into music, Shakespearean drama and dance classes. In college she pursued a bachelor of arts, majoring in drama. Then she encountered psychology.
“I got really stuck on this biological psychology course I took,” Disney said. She soon transferred to Australian National University, where she studied under the noted neuroscientist Michael B. Calford. He introduced her to neurosteroids, a special class of steroids made in the brain that modulate the activity of neurotransmitters, the chemicals that carry information throughout the brain.
During graduate studies at New York University, Disney worked with researchers studying the neurotransmitter acetylcholine. She came across what she thought was an extraordinary claim made by a British neuroscientist: Acetylcholine can sharpen cats’ vision. “I woke up one morning with the realization that I wanted to understand the role of acetylcholine in vision,” Disney said.
For her doctoral thesis, she studied the anatomy of the cholinergic system in the primary cortical vision region of macaques. During her postdoctoral training at The Salk Institute in San Diego, she invented a nanoprobe that can simultaneously monitor acetylcholine levels and electrical activity in the brain.
The probe allows Disney to explore the role that acetylcholine plays in attention and arousal. Rodent studies have shown that acetylcholine release into the cortex promotes attentive states, but the situation appears to be more complex in primates.
When human or nonhuman primates pay close attention to something, they generally concentrate on details in a relatively small area, causing elevated activity in the corresponding region of the visual cortex. “Critics object that the anatomy of release for acetylcholine is too widely spread in the cortex to produce such a focused effect,” Disney said. “Actually, we still know very little about the anatomy of this system, especially in primates.”
Disney theorizes that acetylcholine plays a general role in triggering attention, and another mechanism acts at a smaller scale to cause the local increase in sensitivity to a particular visual stimulus. “Think of the spectrum of capacities from ‘awake but not alert’ to ‘alert and highly attentive.’ I am certain that acetylcholine plays a role some place along this spectrum,” she said. “The question is, where?”
Using her nanoprobe, which Disney will be fabricating in the Vanderbilt Institute for Nanoscale Science and Engineering(VINSE) cleanroom, she plans to explore the cholinergic system in nonhuman primates. And using the functional MRI machines at Vanderbilt’s Institute of Imaging Science, she hopes to do similar studies in humans.